Steel is made by mixing carbon and iron at very high temperatures (above 2600°F).
Carbon is an essential part of making steel. To get pure carbon, the process starts by converting coking coal to coke by driving off the impurities leaving behind pure carbon.
The process involves heating coking coal to around 11000C in the absence of oxygen. This eliminates all the volatile compounds resulting in a hard but porous material known as coke.
The oven used to produce the coke is called a coke battery. It features many coke ovens stacked in rows where the coal is loaded. The process of producing the coke takes 12-36 hours. Once ready, the coke is pushed out and quenched with water or air to cool. It is then stored or transferred to the blast furnace to assist in making iron.
The second stage of making steel begins with making iron. Iron occurs as an oxide in the earth’s crust that can be mined in around 30 countries around the world.
Once the iron ore is mined, it’s fed into a blast furnace along with coke and other minerals like limestones used to collect impurities.
Using nozzles in the lower section of the furnace, air pre-heated to about 12000C is blown into the furnace. As a result, the coke in the furnace burns to produce carbon monoxide, which reacts with the iron ore causing it to melt.
Once all the iron ore is melted, a tap at the bottom of the furnace is opened for the molten iron and impurities to drain off.
The above is a primer on steel production.
